CHMP1A encodes an essential regulator of BMI1-INK4A in cerebellar development

Nat Genet. 2012 Nov;44(11):1260-4. doi: 10.1038/ng.2425. Epub 2012 Sep 30.

Abstract

Charged multivesicular body protein 1A (CHMP1A; also known as chromatin-modifying protein 1A) is a member of the ESCRT-III (endosomal sorting complex required for transport-III) complex but is also suggested to localize to the nuclear matrix and regulate chromatin structure. Here, we show that loss-of-function mutations in human CHMP1A cause reduced cerebellar size (pontocerebellar hypoplasia) and reduced cerebral cortical size (microcephaly). CHMP1A-mutant cells show impaired proliferation, with increased expression of INK4A, a negative regulator of stem cell proliferation. Chromatin immunoprecipitation suggests loss of the normal INK4A repression by BMI in these cells. Morpholino-based knockdown of zebrafish chmp1a resulted in brain defects resembling those seen after bmi1a and bmi1b knockdown, which were partially rescued by INK4A ortholog knockdown, further supporting links between CHMP1A and BMI1-mediated regulation of INK4A. Our results suggest that CHMP1A serves as a critical link between cytoplasmic signals and BMI1-mediated chromatin modifications that regulate proliferation of central nervous system progenitor cells.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Proliferation
  • Cerebellar Cortex* / growth & development
  • Cerebellar Cortex* / metabolism
  • Cyclin-Dependent Kinase Inhibitor p16* / genetics
  • Cyclin-Dependent Kinase Inhibitor p16* / metabolism
  • Endosomal Sorting Complexes Required for Transport* / genetics
  • Endosomal Sorting Complexes Required for Transport* / metabolism
  • Gene Expression Regulation, Developmental
  • Genetic Linkage
  • HEK293 Cells
  • Humans
  • Mice
  • Microcephaly / genetics
  • Microcephaly / metabolism
  • Mitogen-Activated Protein Kinase 7* / genetics
  • Mitogen-Activated Protein Kinase 7* / metabolism
  • Mutation
  • NIH 3T3 Cells
  • Neural Stem Cells / metabolism
  • Neural Stem Cells / pathology
  • Neurons* / metabolism
  • Neurons* / pathology
  • Polymorphism, Single Nucleotide
  • Vesicular Transport Proteins
  • Zebrafish / genetics
  • Zebrafish / growth & development
  • Zebrafish / metabolism

Substances

  • CHMP1A protein, human
  • Cyclin-Dependent Kinase Inhibitor p16
  • Endosomal Sorting Complexes Required for Transport
  • Vesicular Transport Proteins
  • MAPK7 protein, human
  • Mitogen-Activated Protein Kinase 7